Display device, display system, and method of installing electronic component

ABSTRACT

A display device includes a substrate stack including two substrates, a line between the two substrates, and a substrate side line connection part at an end of the line. The display device also includes an electronic component having an electronic component side line connection part. The electronic component side line connection part faces a vertical end surface of the substrate stack. The display device further includes a junction part that electrically joins the vertical end surface and the electronic component. The junction part includes a solder junction part between the substrate side line connection part and the electronic component side line connection part, a resin adhesion part at a region outside the solder junction part that adheres the vertical end surface and the electronic component, and a low-melting junction part between the vertical end surface and the electronic component and formed of a material having a melting point lower than the solder particle.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional application of U.S. patentapplication Ser. No. 15/717,769 filed on Sep. 27, 2017, which claimspriority from and the benefit under 35 U.S.C. § 119(a) of JapanesePatent Application No. 2016-189588 filed on Sep. 28, 2016, which ishereby incorporated by reference in its entirety.

BACKGROUND Technical Field

The present disclosure relates to a display device, a display system,and a method of installing or mounting an electronic component.

Description of the Related Art

Generally, the electronic component for the electronic device isinstalled on a surface of a substrate by joining a pad part of theelectronic component to a line pattern on the substrate.

For example, Japanese Patent Publication No. 2012-226058 discloses aconnection method of the line pattern of the substrate and a lineconnection part of the electronic component by using an anisotropicconductive film (ACF). The anisotropic conductive film includesconductive particles dispersed in a thermosetting resin (thermohardeningresin or thermally-curable resin). The line pattern of the substrate andthe line connection part of the electronic component are electricallyconnected to each other by the anisotropic conductive film.

When the anisotropic conductive film is used as disclosed in JapanesePatent Publication No. 2012-226058, the conductive particles physicallycontact with the line pattern of the substrate and the line connectionpart of the electronic component, and thus the line pattern of thesubstrate and the line connection part of the electronic component areelectrically connected to each other. However, since the conductiveparticles are dispersed in the thermosetting resin, the connectionresistance tends to increase.

In addition, between the substrate and the electronic component, thereexists an insulated part other than the junction part between the linepattern of the substrate and the line connection part of the electroniccomponent. Some of the conductive particles dispersed in thethermosetting resin are interposed between the substrate and theelectronic component corresponding to the insulated part. This decreasesthe insulating properties in the insulated part.

Furthermore, recently in display devices, the display image has becomefiner, and the pitch (interval) of the line pattern of the substrate hasnarrowed to, for example, 100 μm or less. When the line pattern havingthe narrow pitch is used, problems such as an increase in the connectionresistance and a decrease in the insulating properties due to use of theanisotropic conductive film become more significant.

Accordingly, the electrical connection must be increased, therebysuppressing the connection resistance, while firmly bonding theelectronic component to the substrate.

Additionally, in embodiments where the line connection part of theelectronic component is connected to the substrate having the narrowpitch line pattern as described above, high positioning accuracy of theline pattern of the substrate and the line connection part of theelectronic component is required.

However, when the line pattern of the substrate and the line connectionpart of the electronic component are bonded to each other, the linepattern of the substrate and the line connection part of the electroniccomponent may be deviated.

As such, there is a continuing need in the art for a method ofinstalling or mounting electronic components that do not have theselimitations.

BRIEF SUMMARY

Accordingly, the present disclosure is directed to a display device, adisplay system, and a method of installing or mounting an electroniccomponent. The disclosed method substantially obviates one or moretechnological problems due to limitations of the related art.

In at least one embodiment, the present disclosure provides a displaydevice, a display system, and a method of installing or mounting anelectronic component that can align an electronic component with highaccuracy with respect to a line pattern of a substrate board, firmlybond the electronic component to the end surface of the substrate, andincrease the electrical connection, thereby suppressing the connectionresistance.

Additional features and embodiments of the present disclosure will beset forth in the description which follows, and will be apparent fromthe description. The technological improvements of the presentdisclosure will be realized and attained by the structure particularlypointed out in the written description and claims hereof as well as theappended drawings.

In accordance with the present disclosure, as embodied and broadlydescribed herein, there is provided a method of installing an electroniccomponent that includes disposing the electronic component having anelectronic component side line connection part at a vertical end surfaceof a substrate stack including two substrates, a line between the twosubstrates, and a substrate side line connection part at an end of theline. The electronic component side line connection part faces thevertical end surface. The method further includes forming anauto-agglutination solder between the electronic component side lineconnection part and the substrate side line connection part. Theauto-agglutination solder includes a thermosetting resin and a solderparticle. Additionally, the method includes forming a provisionaljunction substance between the vertical end surface of the substratestack and the electronic component, the provisional junction substanceformed of a material having a melting point lower than the solderparticle. The method also includes provisionally junctioning theelectronic component and the vertical end surface of the substrate stackby softening the provisional junction substance at a temperature lowerthan a melting point of the solder particle and the melting point of theprovisional junction substance. The method additionally includespressurizing the electronic component side line connection part and thesubstrate side line connection part by heating-up the auto-agglutinationsolder and the provisional junction substance.

In another embodiment, the present disclosure is directed towards adisplay device includes a substrate stack including two substrates, aline between the two substrates, and a substrate side line connectionpart at an end of the line. The display device further includes anelectronic component having an electronic component side line connectionpart. The electronic component side line connection part faces avertical end surface of the substrate stack. Additionally, the displaydevice includes a junction part that electrically joins the vertical endsurface and the electronic component. The junction part includes asolder junction part between the substrate side line connection part andthe electronic component side line connection part. The junction partalso includes a resin adhesion part at a region outside the solderjunction part that adheres the vertical end surface and the electroniccomponent. The junction part further includes a low-melting junctionpart between the vertical end surface and the electronic component andformed of a material having a melting point lower than the solderparticle.

In another embodiment, the present disclosure is directed towards adisplay system that includes a first display device, a second displaydevice adjacent to the first display device along a first direction, anda third display device adjacent to the first display device along asecond direction. At least one of the first, second, and third displaydevices includes: a substrate stack having two substrates, a linebetween the two substrates, and a substrate side line connection part atan end of the line; an electronic component having an electroniccomponent side line connection part, the electronic component side lineconnection part facing a vertical end surface of the substrate stack;and a junction part that electrically joins the vertical end surface andthe electronic component. The junction part includes a solder junctionpart between the substrate side line connection part and the electroniccomponent side line connection part. The junction part also includes aresin adhesion part at a region outside the solder junction part thatadheres the vertical end surface and the electronic component. Thejunction part further includes a low-melting junction part between thevertical end surface and the electronic component and formed of amaterial having a melting point lower than the solder particle.

The foregoing general description and the following detailed descriptionare by example and explanatory and are intended to provide furtherexplanation of the present disclosure as claimed.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the present disclosure and which are incorporated inand constitute a part of this specification, illustrate embodiments ofthe present disclosure and together with the description serve toexplain the principles of the present disclosure. In the drawings:

FIG. 1 is a schematic cross-sectional view of a portion of a displaydevice according to a first embodiment of the present disclosure.

FIG. 2 is a schematic plane view of a portion of the display device.

FIG. 3 is a view showing an electronic component for the display device.

FIG. 4 is a side view of the display device including a junction pad ata vertical side.

FIG. 5 is a view illustrating a step of coating an auto-agglutinationsolder.

FIG. 6 is a view illustrating a step of starting agglutination of theauto-agglutination solder particles.

FIG. 7 is a view illustrating the junction of the electronic componentto the vertical end surface of the display device by auto-agglutinationof the auto-agglutination solder particles.

FIG. 8 is a perspective view of a display system including the displaydevice.

FIG. 9 is a view illustrating the provisional junction of the electroniccomponent to the vertical end surface of the display device by theprovisional junction sub stance.

FIG. 10 is a schematic cross-sectional view of a portion of a displaydevice according to a second embodiment of the present disclosure.

FIG. 11 is a schematic plane view of a portion of the display device ofFIG. 10.

FIG. 12 is a schematic cross-sectional view of a display panel and anelectronic component provisionally junctioned by a provisional junctionsubstance.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of the disclosure,examples of which are illustrated in the accompanying drawings.

First Embodiment

FIG. 1 is a schematic cross-sectional view of a portion of a displaydevice according to a first embodiment of the present disclosure. FIG. 2is a schematic plane view of a portion of the display device. FIG. 3 isa view showing an electronic component for the display device. FIG. 4 isa side view of the display device including a junction pad at a verticalside. FIG. 5 is a view illustrating a step of coating anauto-agglutination solder. FIG. 6 is a view illustrating a step ofstarting agglutination of the auto-agglutination solder particles. FIG.7 is a view illustrating the junction of the electronic component to thevertical end surface of the display device by auto-agglutination of theauto-agglutination solder particles. FIG. 8 is a perspective view of adisplay system including the display device. FIG. 9 is a viewillustrating the provisional junction of the electronic component to thevertical end surface of the display device by the provisional junctionsubstance.

Referring to FIGS. 1 and 2, a display device 100A includes a displaypanel (e.g., a liquid crystal panel) 110, a light source (not shown)that emits light toward the display panel 110, and a light guiding part(not shown) that guides the light from the light source toward a rearside of the display panel 110. The display panel 110 may be referred toas a substrate stack or a substrate device.

The display panel 110 as the liquid crystal panel includes a firstsubstrate (a substrate) 111, a second substrate (a substrate) 112 facingthe first substrate 111 and a liquid crystal layer (not shown) betweenthe first and second substrates 111 and 112.

Each of the first and second substrates 111 and 112 may be one of aglass substrate, a resin substrate and a print substrate.

Although not shown in the figures, on at least one of the first andsecond substrates 111 and 112 (e.g., the first substrate 111), a linepart (a line) 113, which includes at least one signal line including adata line and a gate line, a thin film transistor, and so on, areformed. The liquid crystal layer is driven by the line part 113 suchthat the display panel 110 displays an image. The line part 113 may havea single-layered structure formed of a low resistance conductivematerial, e.g., aluminum (Al) or copper (Cu). Alternatively, the linepart 113 may have a multi-layered structure including a first layerformed of a lower resistance conductive material, e.g., Al or Cu and asecond layer formed of a conductive material, e.g., chrome (Cr),molybdenum (Mo) or titanium (Ti).

An end 113 e of each line part 113 is a drawout part of the line part113. The end 113 e has a single-layered structure formed of a conductivematerial that is capable of forming an electrical junction with thesolder. The conductive material for the end 113 e of the line part 113may be one of tin (Sn), lead (Pb), zinc (Zn), silver (Ag) and copper(Cu). Alternatively, the end 113 e of the line part 113 may have amulti-layered structure including a first layer of the above conductivematerial and a second layer formed of Cr, Mo or Ti.

In the display panel 110, the end surface 111 s of the first substrate111 and the end surface 112 s of the second substrate 112 are disposedon the same plane. At the end of the display panel 110, a vertical endsurface 110 s, which is perpendicular to a display surface 110 f, isformed (or defined) by the end surface 111 s of the first substrate 111and the end surface 112 s of the second substrate 112.

In the vertical end surface 110 s of the display panel 110, theelectronic component 130 is installed. As shown in FIGS. 1 and 3, theelectronic component 130 may include a line substrate (a film substrate)131 as a film type and a chip component 132, e.g., a large scaleintegration (LSI), installed on a surface 131 f of the line substrate131. For example, the electronic component 130 may be a chip on film(COF). On the surface 131 f of the line substrate 131, a plurality ofconnection electrodes (an electronic component side line connectionpart) 133, which are respectively junctioned with the line parts 113 ofthe display panel 110, are formed. The connection electrode 133 may beformed of a conductive material, e.g., Sn, Pb, Zn, Ag or Cu, that iscapable of junctioning with the solder.

As shown in FIGS. 1 and 4, to install the electronic component 130, aconnection pad (a substrate side line connection part) 200 is junctionedto the end 113 e of each line part 113 between the first and secondsubstrates 111 and 112. The connection pad 200, which has a band shapeand covers a portion of the first substrate 111 and a portion of thesecond substrate 112, is formed along the vertical end surface 110 s ofthe display panel 110. The connection pad 200 may be formed of aconductive material, e.g., Sn, Pb, Zn, Ag or Cu, that is capable ofjunctioning with the solder.

In some embodiments, the connection pad 200 may be formed from a pasteor a nano-ink of Ag or Cu by a screen printing process, a mesh-maskprinting process or an ink-jet process. For example, the connection pad200 may have a width of about 10 to 100 μm, a length of about 0.1 to 1mm and a thickness of about 10 to 1000 nm.

As shown in FIGS. 1 and 2, the electronic component 130 issolder-junctioned to the connection pad 200 at the vertical end surface110 s of the display panel 110 by an auto-agglutination solder 140. Asshown in FIG. 5, the auto-agglutination solder 140 is a paste material.In the auto-agglutination solder 140, a solder particle 140 b formed ofa solder-alloy material, e.g., Cu or Sn, is uniformly dispersed in athermosetting resin 140 a. The thermosetting resin 140 a is formed of amaterial having a melting point lower than the solder particle 140 b. Asthe material for forming the thermosetting resin 140 a, for example, anepoxy resin, a urethane resin, an acrylic resin, a silicone resin, aphenol resin, a melamine resin, an alkyd resin, an urea resin, anunsaturated polyester resin, or the like, which has a melting point of90° C. to 150° C., may be used. Here, the material for forming thethermosetting resin 140 a exhibits fluidity at a temperature of themelting point or more.

For example, ‘Reflow Self Assembly Anisotropic Conductive Paste EpowellAP series’ (SEKISUI CHEMICAL CO., LTD.) or ‘Low-Temperature-Curableconductive’ (Hitachi Chemical Co., Ltd.) may be used as theauto-agglutination solder 140.

In addition, around the auto-agglutination solder 140 junctioning thevertical end surface 110 s of the display panel 110 and the electroniccomponent 130, more particularly, at each of an upper side and a lowerside of the auto-agglutination solder 140, a resin junction part (a lowmelting junction part) 160 is formed of a resin material having amelting point lower than the solder-alloy material for the solderparticle 140 b contained in the auto-agglutination solder 140. The resinjunction part 160 may be formed of, for example, an epoxy resin, aurethane resin, an acrylic resin, a silicone resin, a phenol resin, amelamine resin, an alkyd resin, an urea resin, an unsaturated polyesterresin, or the like, which has a melting point of 90° C. to 150° C.Moreover, the resin material for the resin junction part 160 isthermally cured when it is heated again above the melting point in orderto create a soldering-junction using the auto-agglutination solder 140after provisionally junctioning the electronic component 130 to thevertical end surface 110 s of the display panel 110. This maintains thejunction condition between the electronic component 130 and the verticalend surface 110 s of the display panel 110.

The junction of the electronic component 130 to the connection pad 200at the vertical end surface 110 s of the display panel 110 is made usingthe auto-agglutination solder 140. In some embodiments, theauto-agglutination solder 140 is coated on the vertical end surface 110s of the display panel 110. For example, the auto-agglutination solder140 may be coated by a screen printing process, a mesh-mask printingprocess, or an ink-jet process.

In addition, as shown in FIGS. 4 and 9, at the vertical end surface 110s of the display panel 110, a provisional junction substance 161 iscoated on each of upper and lower sides of a coating area of theauto-agglutination solder 140. In some embodiments, the provisionaljunction substance 161 has a thickness larger than a coating thicknessof the auto-agglutination solder 140 in a direction facing the verticalend surface 110 s of the display panel 110 and the electronic component130. In this manner, the provisional junction substance 161 provided atthe vertical end surface 110 s of the display panel 110 surely contactsthe electronic component 130 during the provisional junctioning to bedescribed later.

Moreover, since the provisional junction substance 161 spreads upwardand downward as compared with a coating area when the auto-agglutinationsolder 140 is thermally bonded, the provisional junction substance 161,beneficially, is provided on a certain position that provisionaljunction substance 161 does not interfere with the auto-agglutinationsolder 140 considering the spread.

Alternatively, the provisional junction substance 161 may be provided ononly one of the upper and lower sides of the coating area of theauto-agglutination solder 140. In addition, the provisional junctionsubstance 161 may be applied to entirely surround the coating area ofthe auto-agglutination solder 140.

Furthermore, the provisional junction substance 161 may have a linearshape continuously formed in a direction along the display surface 110 fof the display panel 110 or may have a dot shape intermittently formedin the direction along the display surface 110 f of the display panel110. The provisional junction substance 161 finally forms the resinjunction part 160. Therefore, the provisional junction substance 161 isthe same material as the resin junction part 160.

The provisional junction substance 161 may be provided ahead at the timeof manufacturing the display panel 110 before application of theauto-agglutination solder 140 or may be provided before or afterapplication of the auto-agglutination solder 140 for electricallyjoining the electronic component 130 to the display panel 110.Alternatively, the provisional junction substance 161 already formed ina predetermined shape may be attached to the vertical end surface 110 sof the display panel 110.

The connection pad 200 at the vertical end surface 110 s of the displaypanel 110 and the connection electrode 133 on the line substrate 131 ofthe electronic component 130 are aligned with a predetermined precisionafter application of the auto-agglutination solder 140 and theprovisional junction part 160.

The provisional junction substance 161 is heated to a temperature lowerthan the melting point of the solder particle 140 b and the meltingpoint of the provisional junction substance 161 by using thethermo-compressing device used in the junction process using theanisotropic conductive film (ACF). Then, the auto-agglutination solder140 is not melted and the provisional junction substance 161 issoftened.

Thereafter, heating the provisional junction substance 161 is stopped.If the temperature of the provisional junction substance 161 decreases,the provisional junction substance 161 is cured, and the electroniccomponent 130 is provisionally junctioned to the vertical end surface110 s of the display panel 110 in a state in which the connection pad200 provided on the vertical end surface 110 s of the display panel 110and the connection electrode 133 formed on the line substrate 131 of theelectronic component 130 are aligned.

Next, the vertical end surface 110 s of the display panel 110 and theelectronic component 130 are pressed towards a direction approachingeach other and heated using the thermo-compressing device used in thejunction process using the anisotropic conductive film (ACF). Apredetermined pressure and a predetermined temperature are applied tothe auto-agglutination solder 140 during a predetermined time (period).For example, the predetermined pressure may be applied to theauto-agglutination solder 140 under the temperature of 150° C. for 15minutes.

As shown in FIG. 6, the thermosetting resin 140 a and the solderparticle 140 b are melted by the applied heat, and the solder particles140 b in the thermosetting resin 140 a which have fluidity areaggregated to each other and become closer to the connection pad 200 andthe connection electrode 133. As a result, as shown in FIG. 7, thesolder particle 140 b is auto-agglutinated and metallically bonded at aspace between the connection pad 200 and the connection electrode 133,which are formed of a metallic material. Namely, the connection pad 200of the display panel 110 and the connection electrode 133 of theelectronic component 130 are soldered by a solder metal (a solderjunction part) “H” formed of a plurality of auto-agglutinated solderparticles 140 b. Additionally, the melted thermosetting resin 140 a isaggregated in a space between adjacent connection pads 200 and/orbetween adjacent connection electrodes 133, such that the line substrate131 of the electronic component 130 and the vertical end surface 110 sof the display panel 110 are attached to each other by an insulatingresin (a resin adhesion part) “P” formed of the thermosetting resin 140a.

The auto-agglutination solder 140 is cooled after the thermo-compressingprocess such that the junction of the electronic component 130 to thevertical end surface 110 s of the display panel 110 is completed.

In addition, while the auto-agglutination solder 140 is heated andpressed in the thermo-compressing process, the provisional junctionsubstance 161 is melted by being heated above the melting point and thenis cured by cooling. At this time, the provisional junction substance161 heated above the melting point is thermally hardened, therebymaintaining the junction condition between the electronic component 130and the vertical end surface 110 s of the display panel 110.

Accordingly, the connection pad 200 at the vertical end surface 110 s ofthe display panel 110 and the connection electrode 133 on the linesubstrate 131 of the electronic component 130 are metallically bonded bythe solder metal H of the auto-agglutination solder 140 such that theconnection pad 200 and the connection electrode 133 are electricallyconnected. In addition, the vertical end surface 110 s of the displaypanel 110 and the line substrate 131 of the electronic component 130 aremechanically attached (or bonded) by the metal bond by the solder metalH and the adhesion by the insulating resin P.

The mechanical junction between the vertical end surface 110 s of thedisplay panel 110 and the line substrate 131 of the electronic component130 by the solder metal H and the insulating resin P may have a tensilestrength being equal to or greater than about 500 g/cm.

Moreover, the line substrate 131 of the electronic component 130 and thevertical end surface 110 s of the display panel 110 are alsomechanically junctioned by the resin junction part 160 formed of thecured provisional junction substance 161.

For example, the solder metal H between the connection pad 200 and theconnection electrode 133 may have a thickness being equal to or lessthan about 20 μm.

A pitch of the connection pad 200 (i.e., a distance between adjacentconnection pads) and a pitch of the connection electrode 133 (i.e., adistance between adjacent connection electrodes) each may be about 10 to100 μm.

As shown in FIGS. 1 and 2, a bezel 150, which forms an outer case of thedisplay device 100A, is installed at a periphery of the display panel110 where the electronic component 130 is installed. For example, thebezel 150 may include a side plate part 150 a at an outer side of thevertical end surface 110 s of the display panel 110 and a front platepart 150 b extending from the side plate part 150 a toward a center ofthe display panel 110 and covering a front edge of the display surface110 f of the display panel 110. The electronic component 130 isaccommodated in a space between the side plate part 150 a of the bezel150 and the vertical end surface 110 s of the display panel 110.

As mentioned above, the vertical end surface 110 s of the display panel110 and the line substrate 131 of the electronic component 130 such thata width “w” of the bezel can be reduced. Namely, a narrow bezel displaydevice 100A is provided.

In addition, as shown in FIG. 8, a plurality of display devices 100A ofthe narrow bezel are arranged to form a display system 1. In the displaysystem 1, the plurality of display devices 100A are adjacently arrangedalong a vertical direction and a horizontal direction. In the displaysystem 1, an image is displayed at a display region “A” formed by theplurality of display devices 100A.

Since the display system 1 includes the narrow bezel display devices100A, a gap between adjacent display devices 100A is reduced such that ahigh quality image is provided at the display region “A.”

An installation method of the electronic component 130 of the presentdisclosure includes disposing the provisional junction substance 161formed of a material having the melting point lower than the solderparticle 140 b of the auto-agglutination solder 140 between the verticalend surface 110 s of the display panel 110 and the electronic component130, while disposing the connection electrode 133 of the electroniccomponent 130 to face the vertical end surface 110 s of the displaypanel 110 including the connection pad 200 at the end 113 e of the linepart 113 between the first substrate 111 and the second substrate 112.The installation method further includes interposing (or coating) theauto-agglutination solder 140, which includes the thermosetting resin140 a and the solder particle 140 b, between the connection electrode133 and the connection pad 200. The installation method also includesprovisionally junctioning the electronic component 130 and the verticalend surface 110 s of the display panel 110 by softening the provisionaljunction substance 161 at the temperature lower than the melting pointof the solder particle 140 b and lower than the melting point of theprovisional junction substance 161. Additionally, the installationmethod includes pressurizing and junctioning the connection electrode133 to the connection pad 200 in a direction approaching each other byheating-up the auto-agglutination solder 140 and the provisionaljunction substance 161.

According to the installation method of the electronic component 130 ofthe present disclosure, since the electronic component 130 and thevertical end surface 110 s of the display panel 110 are provisionallyjunctioned before soldering with the auto-agglutination solder 140, theconnection electrode 133 of the electronic component 130 and theconnection pad 200 can be aligned with a high precision.

The junction process for the electronic component 130 and the displaypanel 110 can be efficiently carried out by soldering with theauto-agglutination solder 140, after provisionally junctioning theelectronic component 130 and the display panel 110 with the provisionaljunction substance 161.

In addition, after performing the provisional junction process with theprovisional junction substance 161, the connection electrode 133 of theelectronic component 130 and the connection pad 200 may be aligned againby heating again and softening the provisional junction substance 161 ifit is before junctioning with the auto-agglutination solder 140.

Moreover, the solder metal H, which is created by the aggregation of thesolder particles 140 b, is formed between the connection electrode 133and the connection pad 200. In comparison to use of ACF, the amount ofthe conductive particles between the connection electrode 133 and theconnection pad 200 is increased such that the increase of the contact(or connection) resistance between the connection electrode 133 and theconnection pad 200 is prevented.

Furthermore, the vertical end surface 110 s of the display panel 110 andthe electronic component 130 are mechanically attached (or bonded) bythe metal bond of the solder metal H of the solder particle 140 b and bythe adhesion of the insulating resin P of the thermosetting resin 140 b.Additionally, the electronic component 130 and the vertical end surface110 s of the display panel 110 are also junctioned around theauto-agglutination solder 140 by the resin junction part 160 (theprovisional junction substance 161). Therefore, the electronic component130 is securely junctioned.

Moreover, in the junction structure of the electronic component 130, thedisplay panel 110, the display device 100A, and the display system 1,there is an junction part “J” that electrically joins the connection pad200 at the vertical end surface 110 s of the display panel 110 (whichincludes the first substrate 111, the second substrate 112 and theconnection pad 200 at the end 113 e of the line part 113 between thefirst and second substrates 111 and 112) with the electronic component130 (which includes the connection electrode 133 facing the vertical endsurface 110 s of the display panel 110). The junction part “J” includesthe solder metal “H” between the connection pad 200 and the connectionelectrode 133, the insulating resin “P” attaching (adhering) thevertical end surface 110 s and the electronic component 130 in a regionoutside the solder metal “H,” and the resin junction part 160 formed ofa material having a lower melting point than the solder metal “H”between the vertical end surface 110 s of the display panel 110 and theelectronic component 130.

In the present disclosure, the electronic component 130 is securelycombined (junctioned or connected) to the vertical end surface 110 s ofthe display panel 110, and the electric connection property is increasedsuch that the increase of the connection resistance (contact resistance)is prevented.

Second Embodiment

FIG. 10 is a schematic cross-sectional view of a portion of a displaydevice according to a second embodiment of the present disclosure. FIG.11 is a schematic plane view of a portion of the display device. FIG. 12is a schematic cross-sectional view of a display panel and an electroniccomponent provisionally junctioned by a provisional junction substance.The same reference numbers are used to the same elements as the firstembodiment, and the explanation for those may be omitted.

Referring to FIGS. 10 and 11, a display device 100B includes a displaypanel (e.g., a liquid crystal panel) 110, a light source (not shown)that emits light toward the display panel 110, and a light guiding part(not shown) that guides the light from the light source toward a rearside of the display panel 110. The display panel 110 may be referred toas a substrate stack or a substrate device.

The display panel 110 as the liquid crystal panel includes a firstsubstrate (a substrate) 111, a second substrate (a substrate) 112 facingthe first substrate 111 and a liquid crystal layer (not shown) betweenthe first and second substrates 111 and 112.

Each of the first and second substrates 111 and 112 may be one of aglass substrate, a resin substrate and a print substrate.

Although not shown in the figures, on at least one of the first andsecond substrates 111 and 112 (e.g., the first substrate 111), a linepart (a line) 113, which includes a signal line including a data lineand a gate line, a thin film transistor, and so on, are formed. Theliquid crystal layer is driven by the line part 113 such that thedisplay device 100A provides an image. The line part 113 may have asingle-layered structure formed of a low resistance conductive material,e.g., aluminum (Al) or copper (Cu). Alternatively, the line part 113 mayhave a multi-layered structure including a first layer formed of a lowerresistance conductive material, e.g., Al or Cu and a second layer formedof a conductive material, e.g., chrome (Cr), molybdenum (Mo) or titanium(Ti).

An end part 113 s of each line part 113 is a drawout part of the linepart 113 and has a single-layered structure formed of a conductivematerial that is capable of forming the electrical junction with thesolder. The conductive material for the end part 113 s of the line part113 may be one of tin (Sn), lead (Pb), zinc (Zn), silver (Ag) and copper(Cu). Alternatively, the end part 113 s of the line part 113 may have amulti-layered structure including a first layer of the above conductivematerial and a second layer formed of Cr, Mo or Ti.

In the display panel 110, the end surface 111 s of the first substrate111 and the end surface 112 s of the second substrate 112 are disposedon the same plane. At the end of the display panel 110, a vertical endsurface 110 s, which is perpendicular to a display surface 110 f, isformed (or defined) by the end surface 111 s of the first substrate 111and the end surface 112 s of the second substrate 112.

At the vertical end surface 110 s of the display panel 110, the end part113 s of the line part 113 (a substrate side line connection part) isdisposed on the same plane with the end surface 111 s of the firstsubstrate 111 and the end surface 112 s of the second substrate 112 suchthat the end part 113 s of the line part 113 is exposed.

At the vertical end surface 110 s of the display panel 110, theelectronic component 130 is installed. The electronic component 130 mayinclude a line substrate (a film substrate) 131 as a film type and achip component 132, e.g., a large scale integration (LSI), installed (orarranged) on a surface 131 f of the line substrate 131. For example, theelectronic component 130 may be a chip on film (COF). On the surface 131f of the line substrate 131, a plurality of connection electrodes (anelectronic component side line connection part) 133, which arerespectively junctioned with the line parts 113 of the display panel110, are formed. The connection electrode 133 may be formed of aconductive material, e.g., Sn, Pb, Zn, Ag or Cu, that is capable ofjunctioning with the solder. A vertical length (length) of theconnection electrode 133 along a direction from the first substrate 111to the second substrate 112 (or the second substrate 112 to the firstsubstrate 111) is larger than that of the substrate side line connectionpart 113 s (i.e., the end of the line part 113).

The electronic component 130 is solder-junctioned to the end part (i.e.,the substrate side line connection part) 113 s of the line part 113,which is exposed at the vertical end surface 110 s of the display panel110, by an auto-agglutination solder 140. As shown in FIG. 5, theauto-agglutination solder 140 is a paste material. In theauto-agglutination solder 140, a solder particle 140 b formed of asolder-alloy material, e.g., Cu or Sn, is uniformly dispersed in athermosetting resin 140 a. The thermosetting resin 140 a is formed of amaterial having a melting point lower than the solder particle 140 b. Asthe material for forming the thermosetting resin 140 a, for example, anepoxy resin, a urethane resin, an acrylic resin, a silicone resin, aphenol resin, a melamine resin, an alkyd resin, an urea resin, anunsaturated polyester resin, or the like, which has a melting point of90° C. to 150° C., may be used. Here, the material for forming thethermosetting resin 140 a exhibits fluidity at a temperature of themelting point or more.

For example, ‘Reflow Self Assembly Anisotropic Conductive Paste EpowellAP series’ (SEKISUI CHEMICAL CO., LTD.) or ‘Low-Temperature-Curableconductive’ (Hitachi Chemical Co., Ltd.) may be used as theauto-agglutination solder 140.

In addition, at each of an upper side and a lower side of theauto-agglutination solder 140 junctioning the vertical end surface 110 sof the display panel 110 and the electronic component 130, a resinjunction part 160 is formed of a resin material having a melting pointlower than the auto-agglutination solder 140. The resin junction part160 may be formed of, for example, an epoxy resin, a urethane resin, anacrylic resin, a silicone resin, a phenol resin, a melamine resin, analkyd resin, an urea resin, an unsaturated polyester resin, or the like,which has a melting point of 90° C. to 150° C. Moreover, the resinmaterial for the resin junction part 160 is thermally cured when it isheated again above the melting point in order to create asolder-junction using the auto-agglutination solder 140 afterprovisionally junctioning the electronic component 130 to the verticalend surface 110 s of the display panel 110. This maintains the junctioncondition between the electronic component 130 and the vertical endsurface 110 s of the display panel 110.

The junction of the electronic component 130 to the end part 113 s atthe vertical end surface 110 s of the display panel 110 is made usingthe auto-agglutination solder 140. In some embodiments, theauto-agglutination solder 140 is coated on the vertical end surface 110s of the display panel 110. For example, the auto-agglutination solder140 of the paste phase may be coated by a screen printing process, amesh-mask printing process, or an ink-jet process.

In addition, as shown in FIG. 12, at the vertical end surface 110 s ofthe display panel 110, a provisional junction substance 161 is coated oneach of upper and lower sides of a coating area of theauto-agglutination solder 140. In some embodiments, the provisionaljunction substance 161 has a thickness larger than a coating thicknessof the auto-agglutination solder 140 in a direction facing the verticalend surface 110 s of the display panel 110 and the electronic component130. In this manner, the provisional junction substance 161 provided atthe vertical end surface 110 s of the display panel 110 surely contactsthe electronic component 130 during the provisional junctioning to bedescribed later.

Moreover, since the provisional junction substance 161 spreads upwardand downward as compared with a coating area when the auto-agglutinationsolder 140 is thermally bonded, the provisional junction substance 161,beneficially, is provided on a certain position that provisionaljunction substance 161 does not interfere with the auto-agglutinationsolder 140 considering the spread.

Alternatively, the provisional junction substance 161 may be provided ononly one of the upper and lower sides of the coating area of theauto-agglutination solder 140. That is, the provisional junctionsubstance 161 may be provided on only one of the end surface 111 s ofthe first substrate 111 and the end surface 112 s of the secondsubstrate 112. In addition, the provisional junction substance 161 maybe applied to entirely surround the coating area of theauto-agglutination solder 140.

Furthermore, the provisional junction substance 161 may have a linearshape continuously formed in a direction along the display surface 110 fof the display panel 110 or may have a dot shape intermittently formedin the direction along the display surface 110 f of the display panel110.

The provisional junction substance 161 finally forms the resin junctionpart 160. Therefore, the provisional junction substance 161 is the samematerial as the resin junction part 160. The provisional junctionsubstance 161 may be provided ahead at the time of manufacturing thedisplay panel 110 before application of the auto-agglutination solder140 or may be provided before or after application of theauto-agglutination solder 140 for electrically joining the electroniccomponent 130 to the display panel 110. Alternatively, the provisionaljunction substance 161 already formed in a predetermined shape may beattached to the vertical end surface 110 s of the display panel 110.

The end part 113 s of the line part 113 exposed at the vertical endsurface 110 s of the display panel 110 and the connection electrode 133on the line substrate 131 of the electronic component 130 are alignedwith a predetermined precision after application of theauto-agglutination solder 140 and the provisional junction part 160.

The provisional junction substance 161 is heated to a temperature lowerthan the melting point of the solder particle 140 b and the meltingpoint of the provisional junction substance 161 by using thethermo-compressing device used in the junction process using anisotropicconductive film (ACF). Then, the auto-agglutination solder 140 is notmelted and the provisional junction substance 161 is softened.

Thereafter, heating the provisional junction substance 161 is stopped.If the temperature of the provisional junction substance 161 decreases,the provisional junction substance 161 is cured, and the electroniccomponent 130 is provisionally junctioned to the vertical end surface110 s of the display panel 110 in a state in which the end part 113 s ofthe line part 113 exposed at the vertical end surface 110 s of thedisplay panel 110 and the connection electrode 133 formed on the linesubstrate 131 of the electronic component 130 are aligned.

Next, the vertical end surface 110 s of the display panel 110 and theelectronic component 130 are pressed in a direction approaching eachother and heated using the thermo-compressing device used in thejunction process using the anisotropic conductive film (ACF). Apredetermined pressure and a predetermined temperature are applied tothe auto-agglutination solder 140 during a predetermined period oftime). For example, the predetermined pressure may be applied to the endpart 113 s of the line part 113 exposed at the vertical end surface 110s of the display panel 110 and the connection electrode 133 on the linesubstrate 131 of the electronic component 130 under the temperature of150° C. for 15 minutes.

As shown in FIGS. 6 and 7, the thermosetting resin 140 a and the solderparticle 140 b are melted by the applied heat, and the solder particles140 b in the thermosetting resin 140 a which have fluidity areaggregated to each other and metallically bonded at a space between theend part 113 s of the line part 113 and the connection electrode 133,which are formed of a metallic material. Namely, the end part 113 s ofthe line part 113 of the display panel 110 and the connection electrode133 of the electronic component 130 are soldered by a solder metal (asolder junction part) “H” formed of a plurality of auto-agglutinatedsolder particles 140 b. Additionally, between the vertical end surface110 s of the display panel 110 and the line substrate 131 of theelectronic component 130, the melted thermosetting resin 140 a isaggregated such that an insulating resin (a resin adhesion part) “P” isformed of the thermosetting resin 140 a in an area other than a portionwhere the solder metal H is formed.

The auto-agglutination solder 140 is cooled after the thermo-compressingprocess such that the junction of the electronic component 130 to thevertical end surface 110 s of the display panel 110 is completed.

In addition, while the auto-agglutination solder 140 is heated andpressed in the thermo-compressing process, the provisional junctionsubstance 161 is melted by being heated above the melting point and thenis cured by cooling. At this time, the provisional junction substance161 heated above the melting point is thermally hardened, therebymaintaining the junction condition between the electronic component 130and the vertical end surface 110 s of the display panel 110.

Accordingly, as shown in FIGS. 10 and 11, the end part 113 s of the linepart 113, which is exposed at the vertical end surface 110 s of thedisplay panel 110 and the connection electrode 133 on the line substrate131 of the electronic component 130 are selectively metallically bondedby the solder metal H of the auto-agglutination solder 140 to beelectrically connected.

In addition, the vertical end surface 110 s of the display panel 110 andthe line substrate 131 of the electronic component 130 are mechanicallyattached (or bonded) by the metal bond using the solder metal H and theadhesion using the insulating resin P.

The mechanical junction between the vertical end surface 110 s of thedisplay panel 110 and the line substrate 131 of the electronic componentby the solder metal H and the insulating resin P may have a tensilestrength being equal to or greater than about 500 g/cm.

Moreover, the line substrate 131 of the electronic component 130 and thevertical end surface 110 s of the display panel 110 are alsomechanically junctioned by the resin junction part 160 formed of thecured provisional junction substance 161.

For example, the solder metal H between the end part 113 s and theconnection electrode 133 may have a thickness being equal to or lessthan about 20 μm.

A pitch of the end part 113 s and a pitch of the connection electrode133 each may be about 10 to 100 μm.

A bezel 150, which forms an outer case of the display device 100B, isinstalled at a periphery of the display panel 110 where the electroniccomponent 130 is installed. For example, the bezel 150 may include aside plate part 150 a at an outer side of the vertical end surface 110 sof the display panel 110 and a front plate part 150 b extending from theside plate part 150 a toward a center of the display panel 110 andcovering a front edge of the display surface 110 f of the display panel110. The electronic component 130 is accommodated in a space between theside plate part 150 a of the bezel 150 and the vertical end surface 110s of the display panel 110.

As mentioned above, the vertical end surface 110 s of the display panel110 and the line substrate 131 of the electronic component 130 such thata width “w” of the bezel can be reduced. Namely, a narrow bezel displaydevice 100B is provided.

In addition, a plurality of display devices 100B of the narrow bezel arearranged to form a display system 1 as shown in FIG. 8. In the displaysystem 1, the plurality of display devices 100B are adjacently arrangedalong a vertical direction and a horizontal direction. In the displaysystem 1, an image is displayed at a display region “A” formed by theplurality of display devices 100B.

Since the display system 1 includes the narrow bezel display devices100B, a gap between adjacent display devices 100B is reduced such that ahigh quality image is provided at the display region “A.”

An installation method of the electronic component 130 of the presentdisclosure includes disposing the provisional junction substance 161formed of a material having the melting point lower than the solderparticle 140 b of the auto-agglutination solder 140 between the verticalend surface 110 s of the display panel 110 and the electronic component130, while disposing the connection electrode 133 of the electroniccomponent 130 to face the vertical end surface 110 s of the displaypanel 110 including the line part 113 installed between the firstsubstrate 111 and the second substrate 112. The installation methodfurther includes interposing (or coating) the auto-agglutination solder140, which includes the thermosetting resin 140 a and the solderparticle 140 b, between the connection electrode 133 and the end part113 s of the line part. The installation method also includesprovisionally junctioning the electronic component 130 and the verticalend surface 110 s of the display panel 110 by softening the provisionaljunction substance 161 at the temperature lower than the melting pointof the solder particle 140 b and lower than the melting point of theprovisional junction substance 161. Additionally, the installationmethod includes pressurizing and junctioning the connection electrode133 to the end part 113 s in a direction approaching each other byheating-up the auto-agglutination solder 140 and the provisionaljunction substance 161.

According to the installation method of the electronic component 130 ofthe present disclosure, since the electronic component 130 and thevertical end surface 110 s of the display panel 110 are provisionallyjunctioned before soldering with the auto-agglutination solder 140, theconnection electrode 133 of the electronic component 130 and the endpart 113 s of the line part 113 can be aligned with a high precision.

The junction process for the electronic component 130 and the displaypanel 110 can be efficiently carried out by soldering with theauto-agglutination solder 140, after provisionally junctioning theelectronic component 130 and the display panel 110 with the provisionaljunction substance 161.

In addition, after performing the provisional junction process with theprovisional junction substance 161, the connection electrode 133 of theelectronic component 130 and the end part 113 s of the line part 113 maybe aligned again by heating again and softening the provisional junctionsubstance 161 if it is before junctioning with the auto-agglutinationsolder 140.

Moreover, the solder metal H, which is created by the aggregation of thesolder particles 140 b, is formed between the connection electrode 133and the end part 113 s of the line part 113. In comparison to use ofACF, the amount of the conductive particles between the connectionelectrode 133 and the end part 113 s of the line part 113 is increasedsuch that the increase of the contact (or connection) resistance betweenthe connection electrode 133 and the end part 113 s of the line part 113is prevented.

Furthermore, the vertical end surface 110 s of the display panel 110 andthe electronic component 130 are mechanically attached (or bonded) bythe metal bond of the solder metal H of the solder particle 140 b and bythe adhesion of the insulating resin P of the thermosetting resin 140 b.Additionally, the electronic component 130 and the vertical end surface110 s of the display panel 110 are also junctioned around theauto-agglutination solder 140 by the resin junction part 160 (theprovisional junction substance 161). Therefore, the electronic component130 is securely junctioned.

Moreover, since the end part 113 s of the line part 113, which isexposed at a space between the first and second substrates 111 and 112,is defined as the substrate side line connection part, the connectionpart 200 is not required as compared with the first embodiment.Accordingly, the process of forming the connection pad 200 is omittedsuch that the production efficiency is increased and the production costis decreased.

Further, in the junction structure of the electronic component 130, thedisplay panel 110, the display device 100B and the display system 1,there is an junction part “J” that electrically joins the end part 113 sof the line part 113 at the vertical end surface 110 s of the displaypanel 110 (which includes the first substrate 111, the second substrate112 and the line part 113 between the first and second substrates 111and 112) with the electronic component 130 (which includes theconnection electrode 133 facing the vertical end surface 110 s of thedisplay panel 110). The junction part “J” includes the solder metal “H”between the end part 113 s of the line part 113 and the connectionelectrode 133, the insulating resin “P” attaching (adhering) thevertical end surface 110 s and the electronic component 130 in a regionoutside the solder metal “H,” and the resin junction part 160 formed ofa material having a lower melting point than the solder metal “H”between the vertical end surface 110 s of the display panel 110 and theelectronic component 130.

In the present disclosure, the electronic component 130 is securelycombined (junctioned or connected) to the vertical end surface 110 s ofthe display panel 110, and the electric connection property is increasedsuch that the increase of the connection resistance (contact resistance)is prevented.

Other Embodiments

The present disclosure is not limited to the embodiments described abovewith reference to the drawings, but various modifications may be made inthe technical scope thereof.

For example, in each of the above embodiments, the provisional junctionsubstance 161 may be provided on the vertical end surface 110 s of theliquid crystal panel 110. However, the provisional junction substance161 may be provided on the electronic component 130 or may be providedon both the vertical end surface 110 s of the display panel 110 and theelectronic component 130.

Moreover, the installing method of the electronic component 130 and thebonding structure of the electronic component 130 shown in each of theabove embodiments can be applied to various electronic devices inaddition to the display devices 100A and 100B.

Furthermore, the display devices 100A and 100B are not limited to theliquid crystal display device, and the present disclosure can besimilarly applied to an organic light emitting diode display device, aplasma display panel display device, and the like.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in a display device of thepresent disclosure without departing from the sprit or scope of theembodiments. Thus, it is intended that the present disclosure covers themodifications and variations of this disclosure provided they comewithin the scope of the appended claims and their equivalents.

The various embodiments described above can be combined to providefurther embodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

The invention claimed is:
 1. A method of installing an electronic component, comprising: positioning the electronic component including an electronic component side line connection part at a vertical end surface of a substrate stack that includes two substrates, a line between the two substrates, and a substrate side line connection part at an end of the line, the electronic component side line connection part facing the vertical end surface; forming an auto-agglutination solder between the electronic component side line connection part and the substrate side line connection part, the auto-agglutination solder including a thermosetting resin and one or more solder particles; forming a provisional junction substance between the vertical end surface of the substrate stack and the electronic component, the provisional junction substance formed of a material having a melting point lower than the one or more solder particles; provisionally junctioning the electronic component and the vertical end surface of the substrate stack by softening the provisional junction substance at a temperature lower than a melting point of the solder particle and the melting point of the provisional junction substance; and heating-up the auto-agglutination solder and the provisional junction substance.
 2. The method according to claim 1, wherein provisional junction substance is positioned around the auto-agglutination solder, which is interposed between the electronic component side line connection part and the substrate side line connection part, between the vertical end side of the substrate stack and the electronic component.
 3. The method according to claim 1, wherein provisional junction substance is provided on at least one of the vertical end surface of the substrate stack and the electronic component.
 4. The method according to claim 1, wherein provisional junction substance is provided on the two substrates at the vertical end surface of the substrate stack.
 5. The method according to claim 1, wherein provisional junction substance is formed of a resin material having a melting point lower than the solder particle.
 6. The method according to claim 1, wherein the substrate side line connection part is connected to the end of the line and formed along the vertical end surface, and the substrate side line connection part is a connection pad formed of a conductive material.
 7. The method according to claim 1, wherein the substrate side line connection part is a portion of the end of the line that is exposed in a space between the two substrates.
 8. The method according to claim 1, wherein the auto-agglutination solder is a paste that is coated on the substrate side line connection part.
 9. The method according to claim 8, wherein the auto-agglutination solder is coated by one of a screen printing process, a mesh-mask printing process, and an ink-jet process.
 10. The method according to claim 1, wherein the electronic component includes a film substrate including the electronic component side line connection part and a chip component on the film substrate.
 11. The method according to claim 1, wherein the line having the substrate side line connection part is formed on at least one of the two substrates.
 12. The method according to claim 1, wherein each of the two substrates is a glass substrate, a resin substrate, or a print substrate.
 13. The method according to claim 1, wherein the substrate stack and the electronic component junctioned at the vertical end surface of the substrate stack form at least one of a liquid crystal display device, an organic light emitting diode display device, and a plasma display panel display device.
 14. The method according to claim 1, wherein the step of heating-up the auto-agglutination solder and the provisional junction substance further includes: pressurizing the electronic component side line connection part and the substrate side line connection part. 